This file describes various problems that have been encountered
in compiling, installing and running XEmacs.

(synched up with: 19.30)

* On Irix, I don't see the toolbar icons and I'm getting lots of
  entries in the warnings buffer.

SGI ships a really old Xpm library in /usr/lib which does not work at
all well with XEmacs.  The solution is to install your own copy of the
latest version of Xpm somewhere and then use the --site-includes and
--site-libraries flags to tell configure where to find it.

* On Digital UNIX, the DEC C compiler might have a problem compiling
  some files.

In particular, src/extents.c and src/faces.c might cause the DEC C
compiler to abort.  When this happens: cd src, compile the files by
hand, cd .., and redo the "make" command.  When recompiling the files by
hand, use the old C compiler for the following versions of Digital UNIX:
  - V3.n: Remove "-migrate" from the compile command.
  - V4.n: Add "-oldc" to the compile command.

* On HPUX, the HP C compiler might have a problem compiling some files
  with optimization.

Richard Cognot <cognot@ensg.u-nancy.fr> writes:

  Had to drop once again to level 2 optimization, at least to
  compile lstream.c. Otherwise, I get a "variable is void: \if"
  problem while dumping (this is a problem I already reported
  with vanilla hpux 10.01 and 9.07, which went away after
  applying patches for the C compiler). Trouble is I still
  haven't found the same patch for hpux 10.10, and I don't
  remember the patch numbers. I think potential XEmacs builders
  on HP should be warned about this.

* On HPUX, you get "poll: Interrupted system call" message in the window
  where XEmacs was launched.

Richard Cognot <cognot@ensg.u-nancy.fr> writes:

  I get a very strange problem when linking libc.a
  dynamically: every event (mouse, keyboard, expose...) results
  in a "poll: Interrupted system call" message in the window
  where XEmacs was launched. Forcing a static link of libc.a
  alone by adding /usr/lib/libc.a at the end of the link line
  solves this. Note that my 9.07 build of 19.14b17 and my (old)
  build of 19.13 both exhibit the same behaviour. I've tried
  various hpux patches to no avail. If this problem cannot be
  solved before the release date, binary kits for HP *must* be
  linked statically against libc, otherwise this problem will
  show up. (This is directed at whoever will volunteer for this
  kit, as I won't be available to do it, unless 19.14 gets
  delayed until mid-june ;-). I think this problem will be an FAQ
  soon after the release otherwise.

* Native cc on SCO OpenServer 5 is now OK.  Icc may still throw you
  a curve.  Here is what Robert Lipe <robertl@arnet.com> says:

Unlike XEmacs 19.13, building with the native cc on SCO OpenServer 5 
now produces a functional binary.   I will typically build this
configuration for COFF with:

	/path_to_XEmacs_source/configure --with-gcc=no \
	  --site-includes=/usr/local/include --site-libraries=/usr/local/lib \
	  --with-xpm --with-xface --with-sound=nas

This version now supports ELF builds.  I highly recommend this to 
reduce the in-core footprint of XEmacs.  This is now how I compile 
all my test releases.  Build it like this:

	/path_to_XEmacs_source/configure --with-gcc=no \
	  --site-includes=/usr/local/include --site-libraries=/usr/local/lib \
	  --with-xpm --with-xface --with-sound=nas --dynamic

The compiler known as icc [ supplied with the OpenServer 5 Development 
System ] generates a working binary, but it takes forever to generate
XEmacs.  ICC also whines more about the code than /bin/cc does.  I do
believe all its whining is legitimate, however.    Note that you do
have to 'cd src ; make  LD=icc' to avoid linker errors.

The way I handle the build procedure is:

	/path_to_XEmacs_source/configure --with-gcc=no \
	  --site-includes=/usr/local/include --site-libraries=/usr/local/lib \
	  --with-xpm --with-xface --with-sound=nas --dynamic --compiler="icc"

*NOTE* I have the xpm, xface, and audio libraries and includes in 
	/usr/local/lib, /usr/local/include.  If you don't have these,
	don't include the "--with-*" arguments in any of my examples.

In previous versions of XEmacs, you had to override the defaults while 
compiling font-lock.o and extents.o when building with icc.  This seems
to no longer be true, but I'm including this old information in case it
resurfaces.  The process I used was:

	make -k    
	[ procure pizza, beer, repeat ] 
	cd src
	make CC="icc -W0,-mP1COPT_max_tree_size=3000" font-lock.o extents.o
	make LD=icc

If you want sound support, get the tls566 supplement from 
ftp.sco.com:/TLS or any of its mirrors.  It works just groovy 
with XEmacs.

The M-x manual-entry is known not to work.  If you know Lisp and would
like help in making it work, e-mail me at <robertl@dgii.com>

In earlier releases, gnuserv/gnuclient/gnudoit would open a frame 
just fine, but the client would lock up and the server would
terminate when you used C-x # to close the frame.   This is now 
fixed in XEmacs.

In etc/ there are two files of note. emacskeys.sco and emacsstrs.sco.
The comments at the top of emacskeys.sco describe its function, and
the emacstrs.sco is a suitable candidate for /usr/lib/keyboard/strings
to take advantage of the keyboard map in emacskeys.sco.

* Don't use -O2 with gcc under Linux without also using
  -fno-strength-reduce.  gcc will generate incorrect code otherwise.
  This bug is present in at least 2.6.x and 2.7.[0-2].  A patched
  binary for 2.7.2 is available in

  ftp://tsx-11.mit.edu/pub/linux/packages/GCC/gcc272-no-sr-bug.lbin.tgz

  Or wait for GCC 2.7.3.

* Under some versions of OSF XEmacs runs fine if built without
optimization but will crash randomly if built with optimization.
Using 'cc -g' is not sufficient to eliminate all optimization.  Try
'cc -g -O0' instead.

* On HP/UX configure selects gcc even though it isn't actually present.

Some versions of SoftBench have an executable called 'gcc' that is not
actually the GNU C compiler.  Use the --with-gcc=no flag when running
configure.


* When Emacs tries to ring the bell, you get an error like

	audio: sst_open: SETQSIZE" Invalid argument
	audio: sst_close: SETREG MMR2, Invalid argument

you have probably compiled using an ANSI C compiler, but with non-ANSI include
files.  In particular, on Suns, the file /usr/include/sun/audioio.h uses the
_IOW macro to define the constant AUDIOSETQSIZE.  _IOW in turn uses a K&R
preprocessor feature that is now explicitly forbidden in ANSI preprocessors,
namely substitution inside character constants.  All ANSI C compilers must 
provide a workaround for this problem.  Lucid's C compiler is shipped with a 
new set of system include files.  If you are using GCC, there is a script
called fixincludes that creates new versions of some system include files that
use this obsolete feature.

* The `Alt' key doesn't behave as `Meta' when running DECwindows.

The default DEC keyboard mapping has the Alt keys set up to generate the
keysym `Multi_key', which has a meaning to xemacs which is distinct from that
of the `Meta_L' and `Meta-R' keysyms.  A second problem is that certain keys
have the Mod2 modifier attached to them for no adequately explored reason.
The correct fix is to pass this file to xmodmap upon starting X:

	clear mod2
	keysym Multi_key = Alt_L
	add mod1 = Alt_L
	add mod1 = Alt_R

* I get complaints about the mapping of my HP keyboard at startup, but I
  haven't changed anything.

The default HP keymap is set up to have Mod1 assigned to two different keys:
Meta_L and Mode_switch (even though there is not actually a Mode_switch key on
the keyboard -- it uses an "imaginary" keycode.)  There actually is a reason
for this, but it's not a good one.  The correct fix is to execute this command
upon starting X:

	xmodmap -e 'remove mod1 = Mode_switch'

* I have focus problems when I use `M-o' to switch to another screen without
  using the mouse.

The focus issues with a program like XEmacs, which has multiple homogeneous
top-level windows, are very complicated, and as a result, most window managers
don't implement them correctly.

The R4/R5 version of twm (and all of its descendants) had buggy focus
handling; there is a patch in .../xemacs/etc/twm-patch which fixes this.
Sufficiently recent versions of tvtwm do not need this patch, but most other
versions of twm do.  If you need to apply this patch, please try to get it
integrated by the maintainer of whichever version of twm you're using.

In addition, if you're using twm, make sure you have not specified
"NoTitleFocus" in your .tvtwmrc file.  The very nature of this option makes
twm do some illegal focus tricks, even with the patch.

It is known that olwm and olvwm are buggy, and in different ways.  If you're 
using click-to-type mode, try using point-to-type, or vice versa.

In older versions of NCDwm, one could not even type at XEmacs windows.  This
has been fixed in newer versions (2.4.3, and possibly earlier).

(Many people suggest that XEmacs should warp the mouse when focusing on
another screen in point-to-type mode.  This is not ICCCM-compliant behavior.
Implementing such policy is the responsibility of the window manager itself,
it is not legal for a client to do this.)

* My buffers are full of \000 characters or otherwise corrupt.

Some compilers have trouble with gmalloc.c and ralloc.c; try recompiling
without optimization.  If that doesn't work, try recompiling with
SYSTEM_MALLOC defined, and/or with REL_ALLOC undefined.

* Some packages that worked before now cause the error
  Wrong type argument: arrayp, #<face ... >

Code which uses the `face' accessor functions must be recompiled with xemacs
19.9 or later.  The functions whose callers must be recompiled are: face-font,
face-foreground, face-background, face-background-pixmap, and face-underline-p.
The .elc files generated by version 19.9 will work in 19.6 and 19.8, but older
.elc files which contain calls to these functions will not work in 19.9.

* On Solaris 2.* I get undefined symbols from libcurses.a.

You probably have /usr/ucblib/ on your LD_LIBRARY_PATH.  Do the link with
LD_LIBRARY_PATH unset.

* I don't have `xmkmf' and `imake' on my HP.

You can get these standard X tools by anonymous FTP to hpcvaaz.cv.hp.com.
Essentially all X programs need these.

* When emacs starts up, I get lots of warnings about unknown keysyms.

If you are running the prebuilt binaries, the Motif library expects to find
certain thing in the XKeysymDB file.  This file is normally in /usr/lib/X11/
or in /usr/openwin/lib/.  If you keep yours in a different place, set the
environment variable $XKEYSYMDB to point to it before starting emacs.  If 
you still have the problem after doing that, perhaps your version of X is 
too old.  There is a copy of the MIT X11R5 XKeysymDB file in the emacs `etc'
directory.  Try using that one.

* My X resources used to work, and now some of them are being ignored.

Check the resources in .../etc/Emacs.ad (which is the same as the file
sample.Xdefaults).  Perhaps some of the default resources built in to 
emacs are now overriding your existing resources.  Copy and edit the
resources in Emacs.ad as necessary.

* Solaris 2.3 /bin/sh coredumps during configuration.

This only occurs if you have LANG != C.  This is a known bug with
/bin/sh fixed by installing Patch-ID# 101613-01.

* "Cannot find callback list" messages from dialog boxes on HPUX, in
Emacs built with Motif.

This problem resulted from a bug in GCC 2.4.5.  Newer GCC versions
such as 2.7.0 fix the problem.

* On Irix 6.0, make tries (and fails) to build a program named unexelfsgi

A compiler bug inserts spaces into the string "unexelfsgi . o"
in src/Makefile.  Edit src/Makefile, after configure is run,
find that string, and take out the spaces.

Compiler fixes in Irix 6.0.1 should eliminate this problem.

* With certain fonts, when the cursor appears on a character, the
character doesn't appear--you get a solid box instead.

One user on a Linux-based GNU system reported that this problem went
away with installation of a new X server.  The failing server was
XFree86 3.1.1.  XFree86 3.1.2 works.

* On SunOS 4.1.3, Emacs unpredictably crashes in _yp_dobind_soft.

This happens if you configure Emacs specifying just `sparc-sun-sunos4'
on a system that is version 4.1.3.  You must specify the precise
version number (or let configure figure out the configuration, which
it can do perfectly well for SunOS).

* On SunOS 4, Emacs processes keep going after you kill the X server
(or log out, if you logged in using X).

Someone reported that recompiling with GCC 2.7.0 fixed this problem.

* On AIX 4, some programs fail when run in a Shell buffer
with an error message like   No terminfo entry for "unknown".

On AIX, many terminal type definitions are not installed by default.
`unknown' is one of them.  Install the "Special Generic Terminal
Definitions" to make them defined.

* On SunOS, you get linker errors
   ld: Undefined symbol 
      _get_wmShellWidgetClass
      _get_applicationShellWidgetClass

The fix to this is to install patch 100573 for OpenWindows 3.0
or link libXmu statically.

* On AIX 4.1.2, linker error messages such as
  ld: 0711-212 SEVERE ERROR: Symbol .__quous, found in the global symbol table
	of archive /usr/lib/libIM.a, was not defined in archive member shr.o.

This is a problem in libIM.a.  You can work around it by executing
these shell commands in the src subdirectory of the directory where
you build Emacs:

    cp /usr/lib/libIM.a .
    chmod 664 libIM.a
    ranlib libIM.a

Then change -lIM to ./libIM.a in the command to link temacs (in
Makefile).

* Unpredictable segmentation faults on Solaris 2.3 and 2.4.

A user reported that this happened in 19.29 when it was compiled with
the Sun compiler, but not when he recompiled with GCC 2.7.0.

We do not know whether something in Emacs is partly to blame for this.

* Emacs exits with "X protocol error" when run with an X server for
Windows.

A certain X server for Windows had a bug which caused this.
Supposedly the newer 32-bit version of this server doesn't have the
problem.

* A position you specified in .Xdefaults is ignored, using twm.

twm normally ignores "program-specified" positions.
You can tell it to obey them with this command in your `.twmrc' file:

  UsePPosition	"on"		#allow clents to request a position

* Compiling lib-src says there is no rule to make test-distrib.c.

This results from a bug in a VERY old version of GNU Sed.  To solve
the problem, install the current version of GNU Sed, then rerun
Emacs's configure script.

* On Sunos 4.1.1, there are errors compiling sysdep.c.

If you get errors such as

    "sysdep.c", line 2017: undefined structure or union
    "sysdep.c", line 2017: undefined structure or union
    "sysdep.c", line 2019: nodename undefined

This can result from defining LD_LIBRARY_PATH.  It is very tricky
to use that environment variable with Emacs.  The Emacs configure
script links many test programs with the system libraries; you must
make sure that the libraries available to configure are the same
ones available when you build Emacs.

* The right Alt key works wrong on German HP keyboards (and perhaps
other non-English HP keyboards too).

This is because HPUX defines the modifiers wrong in X.  Here is a
shell script to fix the problem; be sure that it is run after VUE
configures the X server.

    xmodmap 2> /dev/null - << EOF
    keysym Alt_L = Meta_L
    keysym Alt_R = Meta_R
    EOF

    xmodmap - << EOF
    clear mod1
    keysym Mode_switch = NoSymbol
    add mod1 = Meta_L
    keysym Meta_R = Mode_switch
    add mod2 = Mode_switch
    EOF

* The Emacs window disappears when you type M-q.

Some versions of the Open Look window manager interpret M-q as a quit
command for whatever window you are typing at.  If you want to use
Emacs with that window manager, you should try to configure the window
manager to use some other command.   You can disable the
shortcut keys entirely by adding this line to ~/.OWdefaults:

    OpenWindows.WindowMenuAccelerators: False

* Emacs does not notice when you release the mouse.

There are reports that this happened with (some) Microsoft mice and
that replacing the mouse made it stop.

* Trouble using ptys on IRIX, or running out of ptys.

The program mkpts (which may be in `/usr/adm' or `/usr/sbin') needs to
be set-UID to root, or non-root programs like Emacs will not be able
to allocate ptys reliably.

* On Irix 5.2, unexelfsgi.c can't find cmplrs/stsupport.h.

The file cmplrs/stsupport.h was included in the wrong file set in the
Irix 5.2 distribution.  You can find it in the optional fileset
compiler_dev, or copy it from some other Irix 5.2 system.  A kludgy
workaround is to change unexelfsgi.c to include sym.h instead of
syms.h.

* Slow startup on Linux.

People using systems based on the Linux kernel sometimes report that
startup takes 10 to 15 seconds longer than `usual'.

This is because Emacs looks up the host name when it starts.
Normally, this takes negligible time; the extra delay is due to
improper system configuration.  This problem can occur for both
networked and non-networked machines.

Here is how to fix the configuration.  It requires being root.

** Networked Case

First, make sure the files `/etc/hosts' and `/etc/host.conf' both
exist.  The first line in the `/etc/hosts' file should look like this
(replace HOSTNAME with your host name):

    127.0.0.1      HOSTNAME

Also make sure that the `/etc/host.conf' files contains the following
lines:

    order hosts, bind 
    multi on

Any changes, permanent and temporary, to the host name should be
indicated in the `/etc/hosts' file, since it acts a limited local
database of addresses and names (e.g., some SLIP connections
dynamically allocate ip addresses).

** Non-Networked Case

The solution described in the networked case applies here as well.
However, if you never intend to network your machine, you can use a
simpler solution: create an empty `/etc/host.conf' file.  The command
`touch /etc/host.conf' suffices to create the file.  The `/etc/hosts'
file is not necessary with this approach.

* On Solaris 2.4, Dired hangs and C-g does not work.  Or Emacs hangs
forever waiting for termination of a subprocess that is a zombie.

casper@fwi.uva.nl says the problem is in X11R6.  Rebuild libX11.so
after changing the file xc/config/cf/sunLib.tmpl.  Change the lines

    #if ThreadedX
    #define SharedX11Reqs -lthread
    #endif

to:

    #if OSMinorVersion < 4
    #if ThreadedX
    #define SharedX11Reqs -lthread
    #endif
    #endif

Be sure also to edit x/config/cf/sun.cf so that OSMinorVersion is 4
(as it should be for Solaris 2.4).  The file has three definitions for
OSMinorVersion: the first is for x86, the second for SPARC under
Solaris, and the third for SunOS 4.  Make sure to update the
definition for your type of machine and system.

Then do `make Everything' in the top directory of X11R6, to rebuild
the makefiles and rebuild X.  The X built this way work only on
Solaris 2.4, not on 2.3.

For multithreaded X to work it necessary to install patch
101925-02 to fix problems in header files [2.4].  You need
to reinstall gcc or re-run just-fixinc after installing that
patch.

However, Frank Rust <frust@iti.cs.tu-bs.de> used a simpler solution:
he changed
    #define ThreadedX          YES
to
    #define ThreadedX          NO
in sun.cf and did `make World' to rebuild X11R6.  Removing all
`-DXTHREAD*' flags and `-lthread' entries from lib/X11/Makefile and
typing 'make install' in that directory also seemed to work.

* With M-x enable-flow-control, you need to type C-\ twice
  to do incremental search--a single C-\ gets no response.

This has been traced to communicating with your machine via kermit,
with C-\ as the kermit escape character.  One solution is to use
another escape character in kermit.  One user did

   set escape-character 17

in his .kermrc file, to make C-q the kermit escape character.

* The Motif version of Emacs paints the screen a solid color.

This has been observed to result from the following X resource:

   Emacs*default.attributeFont:	-*-courier-medium-r-*-*-*-140-*-*-*-*-iso8859-*

That the resource has this effect indicates a bug in something, but we
do not yet know what.  If it is an Emacs bug, we hope someone can
explain what the bug is so we can fix it.  In the mean time, removing
the resource prevents the problem.

* Emacs gets hung shortly after startup, on Sunos 4.1.3.

We think this is due to a bug in Sunos.  The word is that
one of these Sunos patches fixes the bug:

100075-11  100224-06  100347-03  100482-05  100557-02  100623-03  100804-03  101080-01
100103-12  100249-09             100496-02  100564-07  100630-02  100891-10  101134-01
100170-09  100296-04  100377-09  100507-04  100567-04  100650-02  101070-01  101145-01
100173-10  100305-15  100383-06  100513-04  100570-05  100689-01  101071-03  101200-02
100178-09  100338-05  100421-03  100536-02  100584-05  100784-01  101072-01  101207-01

We don't know which of these patches really matter.  If you find out
which ones, please inform bug-gnu-emacs@prep.ai.mit.edu.

* Emacs aborts while starting up, only when run without X.

This problem often results from compiling Emacs with GCC when GCC was
installed incorrectly.  The usual error in installing GCC is to
specify --includedir=/usr/include.  Installation of GCC makes
corrected copies of the system header files.  GCC is supposed to use
the corrected copies in preference to the original system headers.
Specifying --includedir=/usr/include causes the original system header
files to be used.  On some systems, the definition of ioctl in the
original system header files is invalid for ANSI C and causes Emacs
not to work.

The fix is to reinstall GCC, and this time do not specify --includedir
when you configure it.  Then recompile Emacs.  Specifying --includedir
is appropriate only in very special cases and it should *never* be the
same directory where system header files are kept.

* The Compose key on a DEC keyboard does not work as Meta key.

This shell command should fix it:

  xmodmap -e 'keycode 0xb1 = Meta_L'

* Regular expressions matching bugs on SCO systems.

On SCO, there are problems in regexp matching when Emacs is compiled
with the system compiler.  The compiler version is "Microsoft C
version 6", SCO 4.2.0h Dev Sys Maintenance Supplement 01/06/93; Quick
C Compiler Version 1.00.46 (Beta).  The solution is to compile with
GCC.

* On Sunos 4, you get the error ld: Undefined symbol __lib_version.

This is the result of using cc or gcc with the shared library meant
for acc (the Sunpro compiler).  Check your LD_LIBRARY_PATH and delete
/usr/lang/SC2.0.1 or some similar directory.

* You can't select from submenus.

On certain systems, mouse-tracking and selection in top-level menus
works properly with the X toolkit, but neither of them works when you
bring up a submenu (such as Bookmarks or Compare or Apply Patch, in
the Files menu).

This works on most systems.  There is speculation that the failure is
due to bugs in old versions of X toolkit libraries, but no one really
knows.  If someone debugs this and finds the precise cause, perhaps a
workaround can be found.

* Unusable default font on SCO 3.2v4.

The Open Desktop environment comes with default X resource settings
that tell Emacs to use a variable-width font.  Emacs cannot use such
fonts, so it does not work.

This is caused by the file /usr/lib/X11/app-defaults/ScoTerm, which is
the application-specific resource file for the `scoterm' terminal
emulator program.  It contains several extremely general X resources
that affect other programs besides `scoterm'.  In particular, these
resources affect Emacs also:

	*Font: -*-helvetica-medium-r-*--12-*-p-*
	*Background:			scoBackground
	*Foreground:			scoForeground

The best solution is to create an application-specific resource file for
Emacs, /usr/lib/X11/app-defaults/Emacs, with the following contents:

	Emacs*Font:	-*-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-1
	Emacs*Background:	white
	Emacs*Foreground:	black

(or whatever other defaults you prefer).

These resource files are not normally shared across a network of SCO
machines; you must create the file on each machine individually.

* rcs2log gives you the awk error message "too many fields".

This is due to an arbitrary limit in certain versions of awk.
The solution is to use gawk (GNU awk).

* Emacs is slow using X11R5 on HP/UX.

This happens if you use the MIT versions of the X libraries--it
doesn't run as fast as HP's version.  People sometimes use the version
because they see the HP version doesn't have the libraries libXaw.a,
libXmu.a, libXext.a and others.  HP/UX normally doesn't come with
those libraries installed.  To get good performance, you need to
install them and rebuild Emacs.

* Loading fonts is very slow.

You might be getting scalable fonts instead of precomputed bitmaps.
Known scalable font directories are "Type1" and "Speedo".  A font
directory contains scalable fonts if it contains the file
"fonts.scale".

If this is so, re-order your X windows font path to put the scalable
font directories last.  See the documentatoin of `xset' for details.

With some X servers, it may be necessary to take the scalable font
directories out of your path entirely, at least for Emacs 19.26.
Changes in the future may make this unnecessary.

* On AIX 3.2.4, releasing Ctrl/Act key has no effect, if Shift is down.

Due to a feature of AIX, pressing or releasing the Ctrl/Act key is
ignored when the Shift, Alt or AltGr keys are held down.  This can
lead to the keyboard being "control-locked"--ordinary letters are
treated as control characters.

You can get out of this "control-locked" state by pressing and
releasing Ctrl/Act while not pressing or holding any other keys.

* display-time causes kernel problems on ISC systems.

Under Interactive Unix versions 3.0.1 and 4.0 (and probably other
versions), display-time causes the loss of large numbers of STREVENT 
cells.  Eventually the kernel's supply of these cells is exhausted.
This makes emacs and the whole system run slow, and can make other 
processes die, in particular pcnfsd.
	
Other emacs functions that communicate with remote processes may have 
the same problem.  Display-time seems to be far the worst.

The only known fix: Don't run display-time.

* On Solaris, C-x doesn't get through to Emacs when you use the console.

This is a Solaris feature (at least on Intel x86 cpus).  Type C-r
C-r C-t, to toggle whether C-x gets through to Emacs.

* Error message `Symbol's value as variable is void: x', followed by
  segmentation fault and core dump.

This has been tracked to a bug in tar!  People report that tar erroneously
added a line like this at the beginning of files of Lisp code:

   x FILENAME, N bytes, B tape blocks

If your tar has this problem, install GNU tar--if you can manage to
untar it :-).

* Link failure when using acc on a Sun.

To use acc, you need additional options just before the libraries, such as

   /usr/lang/SC2.0.1/values-Xt.o -L/usr/lang/SC2.0.1/cg87 -L/usr/lang/SC2.0.1

and you need to add -lansi just before -lc.

The precise file names depend on the compiler version, so we
cannot easily arrange to supply them.

* Link failure on IBM AIX 1.3 ptf 0013.

There is a real duplicate definition of the function `_slibc_free' in
the library /lib/libc_s.a (just do nm on it to verify).  The
workaround/fix is:

    cd /lib
    ar xv libc_s.a NLtmtime.o
    ar dv libc_s.a NLtmtime.o

* Undefined symbols _dlopen, _dlsym and/or _dlclose on a Sun.

If you see undefined symbols _dlopen, _dlsym, or _dlclose when linking
with -lX11, compile and link against the file mit/util/misc/dlsym.c in
the MIT X11R5 distribution.  Alternatively, link temacs using shared
libraries with s/sunos4shr.h.  (This doesn't work if you use the X
toolkit.)

If you get the additional error that the linker could not find
lib_version.o, try extracting it from X11/usr/lib/X11/libvim.a in
X11R4, then use it in the link.

* In Shell mode, you get a ^M at the end of every line.

This happens to people who use tcsh, because it is trying to be too
smart.  It sees that the Shell uses terminal type `unknown' and turns
on the flag to output ^M at the end of each line.  You can fix the
problem by adding this to your .cshrc file:

    if ($?EMACS) then
        if ($EMACS == "t") then
            unset edit 
            stty  -icrnl -onlcr -echo susp ^Z
        endif
    endif

* An error message such as `X protocol error: BadMatch (invalid
parameter attributes) on protocol request 93'.

This comes from having an invalid X resource, such as
   emacs*Cursor:   black
(which is invalid because it specifies a color name for something
that isn't a color.)

The fix is to correct your X resources.

* Undefined symbols when linking on Sunos 4.1.

If you get the undefined symbols _atowc _wcslen, _iswprint, _iswspace,
_iswcntrl, _wcscpy, and _wcsncpy, then you need to add -lXwchar after
-lXaw in the command that links temacs.

This problem seems to arise only when the international language
extensions to X11R5 are installed.

* Typing C-c C-c in Shell mode kills your X server.

This happens with Linux kernel 1.0 thru 1.04, approximately.  The workaround is
to define SIGNALS_VIA_CHARACTERS in config.h and recompile Emacs.
Newer Linux kernel versions don't have this problem.

* src/Makefile and lib-src/Makefile are truncated--most of the file missing.

This can happen if configure uses GNU sed version 2.03.  That version
had a bug.  GNU sed version 2.05 works properly.

* Slow startup on X11R6 with X windows.

If Emacs takes two minutes to start up on X11R6, see if your X
resources specify any Adobe fonts.  That causes the type-1 font
renderer to start up, even if the font you asked for is not a type-1
font.

One way to avoid this problem is to eliminate the type-1 fonts from
your font path, like this:

	xset -fp /usr/X11R6/lib/X11/fonts/Type1/

* Pull-down menus appear in the wrong place, in the toolkit version of Emacs.

An X resource of this form can cause the problem:

   Emacs*geometry:	80x55+0+0

This resource is supposed to apply, and does apply, to the menus
individually as well as to Emacs frames.  If that is not what you
want, rewrite the resource.

To check thoroughly for such resource specifications, use `xrdb
-query' to see what resources the X server records, and also look at
the user's ~/.Xdefaults and ~/.Xdefaults-* files.

* `make install' fails on install-doc with `Error 141'.

This happens on Ultrix 4.2 due to failure of a pipeline of tar
commands.  We don't know why they fail, but the bug seems not to be in
Emacs.  The workaround is to run the shell command in install-doc by
hand.

* Subprocesses remain, hanging but not zombies, on Sunos 5.3.

A bug in Sunos 5.3 causes Emacs subprocesses to remain after Emacs
exits.  Sun patch # 101415-02 is part of the fix for this, but it only
applies to ptys, and doesn't fix the problem with subprocesses
communicating through pipes.

* Mail is lost when sent to local aliases.

Many emacs mail user agents (VM and rmail, for instance) use the
sendmail.el library.  This library can arrange for mail to be
delivered by passing messages to the /usr/lib/sendmail (usually)
program .  In doing so, it passes the '-t' flag to sendmail, which
means that the name of the recipient of the message is not on the
command line and, therefore, that sendmail must parse the message to
obtain the destination address.

There is a bug in the SunOS4.1.1 and SunOS4.1.3 versions of sendmail.
In short, when given the -t flag, the SunOS sendmail won't recognize
non-local (i.e. NIS) aliases.  It has been reported that the Solaris
2.x versions of sendmail do not have this bug.  For those using SunOS
4.1, the best fix is to install sendmail V8 or IDA sendmail (which
have other advantages over the regular sendmail as well).  At the time
of this writing, these official versions are available:

 Sendmail V8 on ftp.cs.berkeley.edu in /ucb/sendmail:
   sendmail.8.6.9.base.tar.Z (the base system source & documentation)
   sendmail.8.6.9.cf.tar.Z   (configuration files)
   sendmail.8.6.9.misc.tar.Z (miscellaneous support programs)
   sendmail.8.6.9.xdoc.tar.Z (extended documentation, with postscript)

 IDA sendmail on vixen.cso.uiuc.edu in /pub:
   sendmail-5.67b+IDA-1.5.tar.gz

* On AIX, you get this message when running Emacs:

    Could not load program emacs
    Symbol smtcheckinit in csh is undefined
    Error was: Exec format error

or this one:

    Could not load program .emacs
    Symbol _system_con in csh is undefined
    Symbol _fp_trapsta in csh is undefined
    Error was: Exec format error

These can happen when you try to run on AIX 3.2.5 a program that was
compiled with 3.2.4.  The fix is to recompile.

* On AIX, you get this compiler error message:

    Processing include file ./XMenuInt.h
        1501-106: (S) Include file X11/Xlib.h not found.

This means your system was installed with only the X11 runtime i.d
libraries.  You have to find your sipo (bootable tape) and install
X11Dev... with smit.

* You "lose characters" after typing Compose Character key.

This is because the Compose Character key is defined as the keysym
Multi_key, and Emacs (seeing that) does the proper X11
character-composition processing.  If you don't want your Compose key
to do that, you can redefine it with xmodmap.

For example, here's one way to turn it into a Meta key:

    xmodmap -e "keysym Multi_key = Meta_L"

If all users at your site of a particular keyboard prefer Meta to
Compose, you can make the remapping happen automatically by adding the
xmodmap command to the xdm setup script for that display.

* C-z just refreshes the screen instead of suspending Emacs.

You are probably using a shell that doesn't support job control, even
though the system itself is capable of it.  Either use a different shell,
or set the variable `cannot-suspend' to a non-nil value.

* Watch out for .emacs files and EMACSLOADPATH environment vars

These control the actions of Emacs.
~/.emacs is your Emacs init file.
EMACSLOADPATH overrides which directories the function
"load" will search.

If you observe strange problems, check for these and get rid
of them, then try again.

* After running emacs once, subsequent invocations crash.

Some versions of SVR4 have a serious bug in the implementation of the
mmap () system call in the kernel; this causes emacs to run correctly
the first time, and then crash when run a second time.

Contact your vendor and ask for the mmap bug fix; in the mean time,
you may be able to work around the problem by adding a line to your
operating system description file (whose name is reported by the
configure script) that reads:
#define SYSTEM_MALLOC
This makes Emacs use memory less efficiently, but seems to work around
the kernel bug.

* Inability to send an Alt-modified key, when Emacs is communicating
directly with an X server.

If you have tried to bind an Alt-modified key as a command, and it
does not work to type the command, the first thing you should check is
whether the key is getting through to Emacs.  To do this, type C-h c
followed by the Alt-modified key.  C-h c should say what kind of event
it read.  If it says it read an Alt-modified key, then make sure you
have made the key binding correctly.

If C-h c reports an event that doesn't have the Alt modifier, it may
be because your X server has no key for the Alt modifier.  The X
server that comes from MIT does not set up the Alt modifier by
default.

If your keyboard has keys named Alt, you can enable them as follows:

    xmodmap -e 'add mod2 = Alt_L'
    xmodmap -e 'add mod2 = Alt_R'

If the keyboard has just one key named Alt, then only one of those
commands is needed.  The modifier `mod2' is a reasonable choice if you
are using an unmodified MIT version of X.  Otherwise, choose any
modifier bit not otherwise used.

If your keyboard does not have keys named Alt, you can use some other
keys.  Use the keysym command in xmodmap to turn a function key (or
some other 'spare' key) into Alt_L or into Alt_R, and then use the
commands show above to make them modifier keys.

Note that if you have Alt keys but no Meta keys, Emacs translates Alt
into Meta.  This is because of the great importance of Meta in Emacs.

* `Pid xxx killed due to text modification or page I/O error'

On HP/UX, you can get that error when the Emacs executable is on an NFS
file system.  HP/UX responds this way if it tries to swap in a page and
does not get a response from the server within a timeout whose default
value is just ten seconds.

If this happens to you, extend the timeout period.

* `expand-file-name' fails to work on any but the machine you dumped Emacs on.

On Ultrix, if you use any of the functions which look up information
in the passwd database before dumping Emacs (say, by using
expand-file-name in site-init.el), then those functions will not work
in the dumped Emacs on any host but the one Emacs was dumped on.

The solution?  Don't use expand-file-name in site-init.el, or in
anything it loads.  Yuck - some solution.

I'm not sure why this happens; if you can find out exactly what is
going on, and perhaps find a fix or a workaround, please let us know.
Perhaps the YP functions cache some information, the cache is included
in the dumped Emacs, and is then inaccurate on any other host.

* On some variants of SVR4, Emacs does not work at all with X.

Try defining BROKEN_FIONREAD in your config.h file.  If this solves
the problem, please send a bug report to tell us this is needed; be
sure to say exactly what type of machine and system you are using.

* Emacs fails to understand most Internet host names, even though
the names work properly with other programs on the same system.
* Emacs won't work with X-windows if the value of DISPLAY is HOSTNAME:0.
* GNUs can't make contact with the specified host for nntp.

This typically happens on Suns and other systems that use shared
libraries.  The cause is that the site has installed a version of the
shared library which uses a name server--but has not installed a
similar version of the unshared library which Emacs uses.

The result is that most programs, using the shared library, work with
the nameserver, but Emacs does not.

The fix is to install an unshared library that corresponds to what you
installed in the shared library, and then relink Emacs.

On SunOS 4.1, simply define HAVE_RES_INIT.

If you have already installed the name resolver in the file libresolv.a,
then you need to compile Emacs to use that library.  The easiest way to
do this is to add to config.h a definition of LIBS_SYSTEM, LIBS_MACHINE
or LIB_STANDARD which uses -lresolv.  Watch out!  If you redefine a macro
that is already in use in your configuration to supply some other libraries,
be careful not to lose the others.

Thus, you could start by adding this to config.h:

#define LIBS_SYSTEM -lresolv

Then if this gives you an error for redefining a macro, and you see that
the s- file defines LIBS_SYSTEM as -lfoo -lbar, you could change config.h
again to say this:

#define LIBS_SYSTEM -lresolv -lfoo -lbar

* On a Sun running SunOS 4.1.1, you get this error message from GNU ld:

    /lib/libc.a(_Q_sub.o): Undefined symbol __Q_get_rp_rd referenced from text segment 

The problem is in the Sun shared C library, not in GNU ld.

The solution is to install Patch-ID# 100267-03 from Sun.

* SunOS 4.1.2: undefined symbol _get_wmShellWidgetClass

  Apparently the version of libXmu.so.a that Sun ships is hosed: it's missing
  some stuff that is in libXmu.a (the static version).  Sun has a patch for 
  this, but a workaround is to use the static version of libXmu, by changing
  the link command from "-lXmu" to "-Bstatic -lXmu -Bdynamic".  If you have
  OpenWindows 3.0, ask Sun for these patches:
    100512-02       4.1.x OpenWindows 3.0 libXt Jumbo patch
    100573-03       4.1.x OpenWindows 3.0 undefined symbols with shared libXmu

* Random other SunOS 4.1.[12] link errors.

  The X headers and libraries that Sun ships in /usr/{include,lib}/X11 are
  broken.  Use the ones in /usr/openwin/{include,lib} instead.

* Bus errors on startup when compiled with Sun's "acc" (in the routine
  make_string_internal() called from initialize_environment_alist())

  The Sun ANSI compiler doesn't place uninitialized static variables in BSS
  space like other compilers do.  This breaks emacs.  If you want to use acc,
  you need to make the file "lastfile.o" be the *first* file in the link 
  command.  Better yet, use Lucid C or GCC.

* The compiler generates lots and lots of syntax errors.

Are you using an ANSI C compiler, like lcc or gcc?  The SunOS 4.1 bundled cc
is not ANSI.

If X has not been configured to compile itself using lcc, gcc, or another ANSI
compiler, then you will have to hack the automatically-generated makefile in
the `lwlib' directory by hand to make it use an ANSI compiler.

* When using gcc, you get the error message "undefined symbol __fixunsdfsi".
* When using gcc, you get the error message "undefined symbol __main".

This means that you need to link with the gcc library.  It may be called
"gcc-gnulib" or "libgcc.a"; figure out where it is, and define LIB_GCC in
config.h to point to it.

It may also work to use the GCC version of `ld' instead of the standard one.

* When compiling with X11, you get "undefined symbol _XtStrings".

This means that you are trying to link emacs against the X11r4 version of
libXt.a, but you have compiled either Emacs or the code in the lwlib
subdirectory with the X11r5 header files.  That doesn't work.

Remember, you can't compile lwlib for r4 and emacs for r5, or vice versa.
They must be in sync.

* Self documentation messages are garbled.

This means that the file `etc/DOC-...' doesn't properly correspond
with the Emacs executable.  Redumping Emacs and then installing the
corresponding pair of files should fix the problem.

* Trouble using ptys on AIX.

People often install the pty devices on AIX incorrectly.
Use `smit pty' to reinstall them properly.

* Shell mode on HP/UX gives the message, "`tty`: Ambiguous".

christos@theory.tn.cornell.edu says:

The problem is that in your .cshrc you have something that tries to
execute `tty`. If you are not running the shell on a real tty then 
tty will print "not a tty". Csh expects one word in some places, 
but tty is giving it back 3.

The solution is to add a pair of quotes around `tty` to make it a single
word: 

if (`tty` == "/dev/console") 

should be changed to:

if ("`tty`" == "/dev/console") 

Even better, move things that set up terminal sections out of .cshrc
and into .login.

* With process-connection-type set to t, each line of subprocess output is
  terminated with a ^M, making ange-ftp and GNUS not work.

On SunOS systems, this problem has been seen to be a result of an incomplete
installation of gcc 2.2 which allowed some non-ANSI compatible include files
into the compilation.  In particular this affected virtually all ioctl() calls.

* Once you pull down a menu from the menubar, it won't go away.

It has been claimed that this is caused by a bug in certain very old (1990?)
versions of the twm window manager.  It doesn't happen with recent vintages,
or with other window managers.

* Emacs ignores the "help" key when running OLWM.

OLWM grabs the help key, and retransmits it to the appropriate client using
XSendEvent.  Allowing emacs to react to synthetic events is a security hole,
so this is turned off by default.  You can enable it by setting the variable
x-allow-sendevents to t.  You can also cause fix this by telling OLWM to not
grab the help key, with the null binding "OpenWindows.KeyboardCommand.Help:".

* Something awful happens when I type M-ESC, instead of `eval-expression'.

MWM intercepts this and several other keys.  Turn this off by adding this to
your resources: "mwm*keyBindings: NoKeyBindings".

* Using X Windows, control-shift-leftbutton makes Emacs hang.

Use the shell command `xset bc' to make the old X Menu package work.

* Emacs running under X Windows does not handle mouse clicks.
* `emacs -geometry 80x20' finds a file named `80x20'.

One cause of such problems is having (setq term-file-prefix nil) in
your .emacs file.  Another cause is a bad value of EMACSLOADPATH in
the environment.

* Emacs gets error message from linker on Sun.

If the error message says that a symbol such as `f68881_used' or
`ffpa_used' or `start_float' is undefined, this probably indicates
that you have compiled some libraries, such as the X libraries, 
with a floating point option other than the default.

It's not terribly hard to make this work with small changes in
crt0.c together with linking with Fcrt1.o, Wcrt1.o or Mcrt1.o.
However, the easiest approach is to build Xlib with the default
floating point option: -fsoft to decide at run time what hardware 
is available.

* Keyboard input gets confused after a beep when using a DECserver
  as a concentrator.

This problem seems to be a matter of configuring the DECserver to use
7 bit characters rather than 8 bit characters.

* M-x shell persistently reports "Process shell exited abnormally with code 1".

This happened on Suns as a result of what is said to be a bug in Sunos
version 4.0.x.  The only fix was to reboot the machine. 

* Programs running under terminal emulator do not recognize `emacs'
  terminal type.

The cause of this is a shell startup file that sets the TERMCAP
environment variable.  The terminal emulator uses that variable to
provide the information on the special terminal type that Emacs
emulates.

Rewrite your shell startup file so that it does not change TERMCAP
in such a case.  You could use the following conditional which sets
it only if it is undefined.

    if ( ! ${?TERMCAP} ) setenv TERMCAP ~/my-termcap-file

Or you could set TERMCAP only when you set TERM--which should not
happen in a non-login shell.

* Problem with remote X server on Suns.

On a Sun, running Emacs on one machine with the X server on another
may not work if you have used the unshared system libraries.  This
is because the unshared libraries fail to use YP for host name lookup.
As a result, the host name you specify may not be recognized.

* Shell mode ignores interrupts on Apollo Domain

You may find that M-x shell prints the following message:

   Warning: no access to tty; thus no job control in this shell...

This can happen if there are not enough ptys on your system.
Here is how to make more of them.

    % cd /dev
    % ls pty*
    # shows how many pty's you have. I had 8, named pty0 to pty7)
    % /etc/crpty 8
    # creates eight new pty's

* Fatal signal in the command  temacs -l loadup inc dump

This command is the final stage of building Emacs.  It is run by the
Makefile in the src subdirectory, or by build.com on VMS.

It has been known to get fatal errors due to insufficient swapping
space available on the machine.

On 68000's, it has also happened because of bugs in the
subroutine `alloca'.  Verify that `alloca' works right, even
for large blocks (many pages).

* test-distrib says that the distribution has been clobbered
* or, temacs prints "Command key out of range 0-127"
* or, temacs runs and dumps xemacs, but xemacs totally fails to work.
* or, temacs gets errors dumping xemacs

This can be because the .elc files have been garbled.  Do not be
fooled by the fact that most of a .elc file is text: these are
binary files and can contain all 256 byte values.

In particular `shar' cannot be used for transmitting GNU Emacs.
It typically truncates "lines".  What appear to be "lines" in
a binary file can of course be of any length.  Even once `shar'
itself is made to work correctly, `sh' discards null characters
when unpacking the shell archive.

I have also seen character \177 changed into \377.  I do not know
what transfer means caused this problem.  Various network
file transfer programs are suspected of clobbering the high bit.

If you have a copy of Emacs that has been damaged in its
nonprinting characters, you can fix them:

 1) Record the names of all the .elc files.
 2) Delete all the .elc files.
 3) Recompile alloc.c with a value of PURESIZE twice as large.
     You might as well save the old alloc.o.
 4) Remake xemacs.  It should work now.
 5) Running xemacs, do Meta-x byte-compile-file repeatedly
  to recreate all the .elc files that used to exist.
  You may need to increase the value of the variable
  max-lisp-eval-depth to succeed in running the compiler interpreted
  on certain .el files.  400 was sufficient as of last report.
 6) Reinstall the old alloc.o (undoing changes to alloc.c if any)
  and remake temacs.
 7) Remake xemacs.  It should work now, with valid .elc files.

* temacs prints "Pure Lisp storage exhausted"

This means that the Lisp code loaded from the .elc and .el
files during  temacs -l loadup inc dump  took up more
space than was allocated.

This could be caused by
 1) adding code to the preloaded Lisp files
 2) adding more preloaded files in loadup.el
 3) having a site-init.el or site-load.el which loads files.
   Note that ANY site-init.el or site-load.el is nonstandard;
   if you have received Emacs from some other site
   and it contains a site-init.el or site-load.el file, consider
   deleting that file.
 4) getting the wrong .el or .elc files
   (not from the directory you expected).
 5) deleting some .elc files that are supposed to exist.
   This would cause the source files (.el files) to be
   loaded instead.  They take up more room, so you lose.
 6) a bug in the Emacs distribution which underestimates
   the space required.

If the need for more space is legitimate, use the --puresize option
to `configure' to specify more pure space.

But in some of the cases listed above, this problem is a consequence
of something else that is wrong.  Be sure to check and fix the real
problem.

* Changes made to .el files do not take effect.

You may have forgotten to recompile them into .elc files.
Then the old .elc files will be loaded, and your changes
will not be seen.  To fix this, do M-x byte-recompile-directory
and specify the directory that contains the Lisp files.

Note that you may get a warning when loading a .elc file that
is older than the corresponding .el file.

* Things which should be bold or italic (such as the initial copyright notice)
  are not.

The fonts of the "bold" and "italic" faces are generated from the font of
the "default" face; in this way, your bold and italic fonts will have the
appropriate size and family.  However, emacs can only be clever in this
way if you have specified the default font using the XLFD (X Logical Font
Description) format, which looks like

	*-courier-medium-r-*-*-*-120-*-*-*-*-*-*

if you use any of the other, less strict font name formats, some of which
look like
		lucidasanstypewriter-12
and		fixed
and		9x13

then emacs won't be able to guess the names of the "bold" and "italic"
versions.  All X fonts can be referred to via XLFD-style names, so you
should use those forms.  See the man pages for X(1), xlsfonts(1), and
xfontsel(1).

* The dumped Emacs (xemacs) crashes when run, trying to write pure data.

Two causes have been seen for such problems.

1) On a system where getpagesize is not a system call, it is defined
as a macro.  If the definition (in both unexec.c and malloc.c) is wrong,
it can cause problems like this.  You might be able to find the correct
value in the man page for a.out (5).

2) Some systems allocate variables declared static among the
initialized variables.  Emacs makes all initialized variables in most
of its files pure after dumping, but the variables declared static and
not initialized are not supposed to be pure.  On these systems you
may need to add "#define static" to the m- or the s- file.

* Reading and writing files is very very slow.

Try evaluating the form (setq lock-directory nil) and see if that helps.
There is a problem with file-locking on some systems (possibly related
to NFS) that I don't understand.  Please send mail to the address 
xemacs@xemacs.org if you figure this one out.

* Compilation errors on VMS.

Sorry, XEmacs does not work under VMS.  You might consider working on
the port if you really want to have XEmacs work under VMS.

* "Symbol's value as variable is void: unread-command-char".
* "Wrong type argument: arrayp, #<keymap 143 entries>"
* "Wrong type argument: stringp, [#<keypress-event return>]"

There are a few incompatible changes in XEmacs, and these are the
symptoms.  Some of the emacs-lisp code you are running needs to be
updated to be compatible with XEmacs.

We have provided modified versions of several popular emacs packages (GNUS, 
VM, etc) which are compatible with this version of emacs.  Check to make
sure you have not set your load-path so that your private copies of these
packages are being found before the versions in the lisp directory.

Make sure that your load-path and your $EMACSLOADPATH environment variable
are not pointing at an Emacs18 lisp directory.  This will cripple emacs.

* rmail or VM gets error getting new mail

rmail and VM get new mail from /usr/spool/mail/$USER using a program
called `movemail'.  This program interlocks with /bin/mail using
the protocol defined by /bin/mail.

There are two different protocols in general use.  One of them uses
the `flock' system call.  The other involves creating a lock file;
`movemail' must be able to write in /usr/spool/mail in order to do
this.  You control which one is used by defining, or not defining,
the macro MAIL_USE_FLOCK in config.h or the m- or s- file it includes.
IF YOU DON'T USE THE FORM OF INTERLOCKING THAT IS NORMAL ON YOUR
SYSTEM, YOU CAN LOSE MAIL!

If your system uses the lock file protocol, and fascist restrictions
prevent ordinary users from writing the lock files in /usr/spool/mail,
you may need to make `movemail' setgid to a suitable group such as
`mail'.  You can use these commands (as root):

	chgrp mail movemail
	chmod 2755 movemail

If your system uses the lock file protocol, and fascist restrictions
prevent ordinary users from writing the lock files in /usr/spool/mail,
you may need to make `movemail' setgid to a suitable group such as
`mail'.  To do this,  use the following commands (as root) after doing the
make install.

	chgrp mail movemail
	chmod 2755 movemail

Installation normally copies movemail from the build directory to an
installation directory which is usually under /usr/local/lib.  The
installed copy of movemail is usually in the directory
/usr/local/lib/emacs/VERSION/TARGET.  You must change the group and
mode of the installed copy; changing the group and mode of the build
directory copy is ineffective.

* Emacs spontaneously displays "I-search: " at the bottom of the screen.

This means that Control-S/Control-Q (XON/XOFF) "flow control" is being
used.  C-s/C-q flow control is bad for Emacs editors because it takes
away C-s and C-q as user commands.  Since editors do not output long
streams of text without user commands, there is no need for a
user-issuable "stop output" command in an editor; therefore, a
properly designed flow control mechanism would transmit all possible
input characters without interference.  Designing such a mechanism is
easy, for a person with at least half a brain.

There are three possible reasons why flow control could be taking place:

  1) Terminal has not been told to disable flow control
  2) Insufficient padding for the terminal in use
  3) Some sort of terminal concentrator or line switch is responsible

First of all, many terminals have a set-up mode which controls whether
they generate XON/XOFF flow control characters.  This must be set to
"no XON/XOFF" in order for Emacs to work.  Sometimes there is an
escape sequence that the computer can send to turn flow control off
and on.  If so, perhaps the termcap `ti' string should turn flow
control off, and the `te' string should turn it on.

Once the terminal has been told "no flow control", you may find it
needs more padding.  The amount of padding Emacs sends is controlled
by the termcap entry for the terminal in use, and by the output baud
rate as known by the kernel.  The shell command `stty' will print
your output baud rate; `stty' with suitable arguments will set it if
it is wrong.  Setting to a higher speed causes increased padding.  If
the results are wrong for the correct speed, there is probably a
problem in the termcap entry.  You must speak to a local Unix wizard
to fix this.  Perhaps you are just using the wrong terminal type.

For terminals that lack a "no flow control" mode, sometimes just
giving lots of padding will prevent actual generation of flow control
codes.  You might as well try it.

If you are really unlucky, your terminal is connected to the computer
through a concentrator which sends XON/XOFF flow control to the
computer, or it insists on sending flow control itself no matter how
much padding you give it.  Unless you can figure out how to turn flow
control off on this concentrator (again, refer to your local wizard),
you are screwed!  You should have the terminal or concentrator
replaced with a properly designed one.  In the mean time, some drastic
measures can make Emacs semi-work.

You can make Emacs ignore C-s and C-q and let the operating system
handle them.  To do this on a per-session basis, just type M-x
enable-flow-control RET.  You will see a message that C-\ and C-^ are
now translated to C-s and C-q.  (Use the same command M-x
enable-flow-control to turn *off* this special mode.  It toggles flow
control handling.)

If C-\ and C-^ are inconvenient for you (for example, if one of them
is the escape character of your terminal concentrator), you can choose
other characters by setting the variables flow-control-c-s-replacement
and flow-control-c-q-replacement.  But choose carefully, since all
other control characters are already used by emacs.

IMPORTANT: if you type C-s by accident while flow control is enabled,
Emacs output will freeze, and you will have to remember to type C-q in
order to continue.

If you work in an environment where a majority of terminals of a
certain type are flow control hobbled, you can use the function
`enable-flow-control-on' to turn on this flow control avoidance scheme
automatically.  Here is an example:

(enable-flow-control-on "vt200" "vt300" "vt101" "vt131")

If this isn't quite correct (e.g. you have a mixture of flow-control hobbled
and good vt200 terminals), you can still run enable-flow-control
manually.

I have no intention of ever redesigning the Emacs command set for the
assumption that terminals use C-s/C-q flow control.  XON/XOFF flow
control technique is a bad design, and terminals that need it are bad
merchandise and should not be purchased.  Now that X is becoming
widespread, XON/XOFF seems to be on the way out.  If you can get some
use out of GNU Emacs on inferior terminals, more power to you, but I
will not make Emacs worse for properly designed systems for the sake
of inferior systems.

* Control-S and Control-Q commands are ignored completely.

For some reason, your system is using brain-damaged C-s/C-q flow
control despite Emacs's attempts to turn it off.  Perhaps your
terminal is connected to the computer through a concentrator
that wants to use flow control.

You should first try to tell the concentrator not to use flow control.
If you succeed in this, try making the terminal work without
flow control, as described in the preceding section.

If that line of approach is not successful, map some other characters
into C-s and C-q using keyboard-translate-table.  The example above
shows how to do this with C-^ and C-\.

* Control-S and Control-Q commands are ignored completely on a net connection.

Some versions of rlogin (and possibly telnet) do not pass flow
control characters to the remote system to which they connect.
On such systems, emacs on the remote system cannot disable flow
control on the local system.

One way to cure this is to disable flow control on the local host
(the one running rlogin, not the one running rlogind) using the
stty command, before starting the rlogin process.  On many systems,
"stty start u stop u" will do this.

Some versions of tcsh will prevent even this from working.  One way
around this is to start another shell before starting rlogin, and
issue the stty command to disable flow control from that shell.

If none of these methods work, the best solution is to type
M-x enable-flow-control at the beginning of your emacs session, or
if you expect the problem to continue, add a line such as the
following to your .emacs (on the host running rlogind):

(enable-flow-control-on "vt200" "vt300" "vt101" "vt131")

See the entry about spontaneous display of I-search (above) for more
info.

* Screen is updated wrong, but only on one kind of terminal.

This could mean that the termcap entry you are using for that
terminal is wrong, or it could mean that Emacs has a bug handing
the combination of features specified for that terminal.

The first step in tracking this down is to record what characters
Emacs is sending to the terminal.  Execute the Lisp expression
(open-termscript "./emacs-script") to make Emacs write all
terminal output into the file ~/emacs-script as well; then do
what makes the screen update wrong, and look at the file
and decode the characters using the manual for the terminal.
There are several possibilities:

1) The characters sent are correct, according to the terminal manual.

In this case, there is no obvious bug in Emacs, and most likely you
need more padding, or possibly the terminal manual is wrong.

2) The characters sent are incorrect, due to an obscure aspect
 of the terminal behavior not described in an obvious way
 by termcap.

This case is hard.  It will be necessary to think of a way for
Emacs to distinguish between terminals with this kind of behavior
and other terminals that behave subtly differently but are
classified the same by termcap; or else find an algorithm for
Emacs to use that avoids the difference.  Such changes must be
tested on many kinds of terminals.

3) The termcap entry is wrong.

See the file etc/TERMS for information on changes
that are known to be needed in commonly used termcap entries
for certain terminals.

4) The characters sent are incorrect, and clearly cannot be
 right for any terminal with the termcap entry you were using.

This is unambiguously an Emacs bug, and can probably be fixed
in termcap.c, tparam.c, term.c, scroll.c, cm.c or dispnew.c.

* Output from Control-V is slow.

On many bit-map terminals, scrolling operations are fairly slow.
Often the termcap entry for the type of terminal in use fails
to inform Emacs of this.  The two lines at the bottom of the screen
before a Control-V command are supposed to appear at the top after
the Control-V command.  If Emacs thinks scrolling the lines is fast,
it will scroll them to the top of the screen.

If scrolling is slow but Emacs thinks it is fast, the usual reason is
that the termcap entry for the terminal you are using does not
specify any padding time for the `al' and `dl' strings.  Emacs
concludes that these operations take only as much time as it takes to
send the commands at whatever line speed you are using.  You must
fix the termcap entry to specify, for the `al' and `dl', as much
time as the operations really take.

Currently Emacs thinks in terms of serial lines which send characters
at a fixed rate, so that any operation which takes time for the
terminal to execute must also be padded.  With bit-map terminals
operated across networks, often the network provides some sort of
flow control so that padding is never needed no matter how slow
an operation is.  You must still specify a padding time if you want
Emacs to realize that the operation takes a long time.  This will
cause padding characters to be sent unnecessarily, but they do
not really cost much.  They will be transmitted while the scrolling
is happening and then discarded quickly by the terminal.

Most bit-map terminals provide commands for inserting or deleting
multiple lines at once.  Define the `AL' and `DL' strings in the
termcap entry to say how to do these things, and you will have
fast output without wasted padding characters.  These strings should
each contain a single %-spec saying how to send the number of lines
to be scrolled.  These %-specs are like those in the termcap
`cm' string.

You should also define the `IC' and `DC' strings if your terminal
has a command to insert or delete multiple characters.  These
take the number of positions to insert or delete as an argument.

A `cs' string to set the scrolling region will reduce the amount
of motion you see on the screen when part of the screen is scrolled.

* Your Delete key sends a Backspace to the terminal, using an AIXterm.

The solution is to include in your .Xdefaults the lines:

   *aixterm.Translations: #override <Key>BackSpace: string(0x7f)
   aixterm*ttyModes: erase ^?

This makes your Backspace key send DEL (ASCII 127).

* You type Control-H (Backspace) expecting to delete characters.

Emacs has traditionally used Control-H for help; unfortunately
this interferes with its use as Backspace on TTY's.  This has not
been fixed due to an incredible arrogance on RMS's part.  One way
to solve this problem is to put this in your .emacs:

  (global-set-key "\b" 'delete-backward-char)
  (global-set-key "\M-h" 'help-command)

This makes Control-H (Backspace) work sensibly, and moves help to
Meta-H (ESC H).

Note that you can probably also access help using F1.

* Editing files through RFS gives spurious "file has changed" warnings.
It is possible that a change in Emacs 18.37 gets around this problem,
but in case not, here is a description of how to fix the RFS bug that
causes it.

    There was a serious pair of bugs in the handling of the fsync() system
    call in the RFS server.

    The first is that the fsync() call is handled as another name for the
    close() system call (!!).  It appears that fsync() is not used by very
    many programs; Emacs version 18 does an fsync() before closing files
    to make sure that the bits are on the disk.

    This is fixed by the enclosed patch to the RFS server.

    The second, more serious problem, is that fsync() is treated as a
    non-blocking system call (i.e., it's implemented as a message that
    gets sent to the remote system without waiting for a reply).  Fsync is
    a useful tool for building atomic file transactions.  Implementing it
    as a non-blocking RPC call (when the local call blocks until the sync
    is done) is a bad idea; unfortunately, changing it will break the RFS
    protocol.  No fix was supplied for this problem.

    (as always, your line numbers may vary)

    % rcsdiff -c -r1.2 serversyscall.c
    RCS file: RCS/serversyscall.c,v
    retrieving revision 1.2
    diff -c -r1.2 serversyscall.c
    *** /tmp/,RCSt1003677   Wed Jan 28 15:15:02 1987
    --- serversyscall.c     Wed Jan 28 15:14:48 1987
    ***************
    *** 163,169 ****
	    /*
	     * No return sent for close or fsync!
	     */
    !       if (syscall == RSYS_close || syscall == RSYS_fsync)
		    proc->p_returnval = deallocate_fd(proc, msg->m_args[0]);
	    else
	    {
    --- 166,172 ----
	    /*
	     * No return sent for close or fsync!
	     */
    !       if (syscall == RSYS_close)
		    proc->p_returnval = deallocate_fd(proc, msg->m_args[0]);
	    else
	    {

* Vax C compiler bugs affecting Emacs.

You may get one of these problems compiling Emacs:

   foo.c line nnn: compiler error: no table entry for op STASG
   foo.c: fatal error in /lib/ccom

These are due to bugs in the C compiler; the code is valid C.
Unfortunately, the bugs are unpredictable: the same construct
may compile properly or trigger one of these bugs, depending
on what else is in the source file being compiled.  Even changes
in header files that should not affect the file being compiled
can affect whether the bug happens.  In addition, sometimes files
that compile correctly on one machine get this bug on another machine.

As a result, it is hard for me to make sure this bug will not affect
you.  I have attempted to find and alter these constructs, but more
can always appear.  However, I can tell you how to deal with it if it
should happen.  The bug comes from having an indexed reference to an
array of Lisp_Objects, as an argument in a function call:
  Lisp_Object *args;
  ...
   ... foo (5, args[i], ...)...
putting the argument into a temporary variable first, as in
  Lisp_Object *args;
  Lisp_Object tem;
  ...
   tem = args[i];
   ... foo (r, tem, ...)...
causes the problem to go away.
The `contents' field of a Lisp vector is an array of Lisp_Objects,
so you may see the problem happening with indexed references to that.

* 68000 C compiler problems

Various 68000 compilers have different problems.
These are some that have been observed.

** Using value of assignment expression on union type loses.
This means that  x = y = z;  or  foo (x = z);  does not work
if x is of type Lisp_Object.

** "cannot reclaim" error.

This means that an expression is too complicated.  You get the correct
line number in the error message.  The code must be rewritten with
simpler expressions.

** XCONS, XSTRING, etc macros produce incorrect code.

If temacs fails to run at all, this may be the cause.
Compile this test program and look at the assembler code:

struct foo { char x; unsigned int y : 24; };

lose (arg)
     struct foo arg;
{
  test ((int *) arg.y);
}

If the code is incorrect, your compiler has this problem.
In the XCONS, etc., macros in lisp.h you must replace (a).u.val with
((a).u.val + coercedummy) where coercedummy is declared as int.

This problem will not happen if the m-...h file for your type
of machine defines NO_UNION_TYPE.  That is the recommended setting now.

* C compilers lose on returning unions

I hear that some C compilers cannot handle returning a union type.
Most of the functions in GNU Emacs return type Lisp_Object, which is
defined as a union on some rare architectures.

This problem will not happen if the m-...h file for your type
of machine defines NO_UNION_TYPE.  That is the recommended setting now.
